Clinical Features and Outcomes of Acute Exacerbation in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Heart Disease: A Multicenter Observational Study

Figures & data

Figure 1 Flow chart of obtaining the study population.

Abbreviations: ACURE, acute exacerbation of chronic obstructive pulmonary disease inpatient registry; AECOPD, acute exacerbation of chronic obstructive pulmonary disease; PHD, pulmonary heart disease.

Table 1 The Demographics, Smoking Status and Comorbidity of Study Population

Variables	Non-PHD Group (n = 3277)	PHD Group (n = 1109)	P value
Age (years)	69.77±9.33	69.11±8.99	0.041
Sex			0.996
Female	671 (20.48%)	227 (20.47%)
Male	2606 (79.52%)	882 (79.53%)
Body mass index (kg/m^2)	22.01±3.54	21.99±3.90	0.897
Smoking history			0.011
Never	988 (30.15%)	337 (30.39%)
Current	833 (25.42%)	235 (21.19%)
Former	1456 (44.43%)	537 (48.42%)
Comorbidity
Bronchiectasis	520 (15.87%)	208 (18.76%)	0.026
Pulmonary fibrosis	407 (12.42%)	182 (16.41%)	<0.01
Sleep apnea syndrome	41 (1.25%)	17 (1.53%)	0.478
Cancer	84 (2.56%)	32 (2.89%)	0.563
PTE	17 (0.52%)	5 (0.45%)	0.782
VTE	337 (10.28%)	126 (11.36%)	0.313
Atrial fibrillation	119 (3.63%)	42 (3.79%)	0.812
Chronic heart failure	162 (4.94%)	132 (11.90%)	<0.01
Hypertension	1197 (36.53%)	443 (39.95%)	0.042
Coronary heart disease	629 (19.19%)	192 (17.31%)	0.165
Chronic kidney disease	56 (1.71%)	18 (1.62%)	0.848
Diabetes mellitus	361 (11.02%)	112 (10.10%)	0.395

Notes: For continuous variables, mean and standard deviation were used for data with normal distribution, while median and interquartile range were described to non-normal data. For categorical variables, frequencies and percentages were demonstrated.

Abbreviations: Non-PHD, without pulmonary heart disease; PHD, pulmonary heart disease; PTE, Pulmonary thromboembolism; VTE, venous thromboembolism.

Table 2 The Clinical Features of AECOPD Patients

Variables	Non-PHD Group (n = 3277)	PHD Group (n = 1109)	P value
PFT (Post-bronchodilator)
FEV1/FVC	0.51[0.42,0.59]	0.48[0.40,0.57]	<0.01
FVC (L)	1.95[1.45,2.49]	1.90[1.40,2.43]	0.018
FEV1 (L)	0.94[0.66,1.30]	0.84[0.60,1.23]	<0.01
FEV1/predicted	0.40[0.29,0.56]	0.37[0.26,0.53]	<0.01
GOLD grade			<0.01
GOLD1	154 (5.77%)	59 (6.13%)
GOLD2	753 (28.22%)	220 (22.87%)
GOLD3	1013 (37.97%)	353 (36.69%)
GOLD4	748 (28.04%)	330 (34.30%)
Frequency of hospitalization due to AECOPD in past year (times)			0.033
0	1469 (44.83%)	456 (41.12%)
≥1	1808 (55.17%)	653 (58.88%)
CAT score	19.86±6.95	21.14±7.12	<0.01
mMRC score	3.00[2.00,3.00]	3.00[2.00,4.00]	<0.01
Pulse	88.75±16.14	90.44±16.49	<0.01
PaCO2 (mmHg)	45.28±12.67	48.37±13.78	<0.01
PaO2 (mmHg)	78.26±26.71	71.89±24.83	<0.01

Notes: For continuous variables, mean and standard deviation were used for data with normal distribution, while median and interquartile range were described to non-normal data. For categorical variables, frequencies and percentages were demonstrated.

Abbreviations: AECOPD, acute exacerbation of chronic obstructive pulmonary disease; Non-PHD, without pulmonary heart disease; PHD, pulmonary heart disease; FVC, forced vital capacity; FEV₁, forced expiratory volume in one second; GOLD, global initiative for chronic obstructive lung disease; AECOPD, acute exacerbation of chronic obstructive pulmonary disease; CAT, COPD assessment test; mMRC, modified British Medical Research Council; GOLD1, FEV₁% predicted≥80; GODL2, 50≤FEV₁% predicted<80; GOLD3, 30≤FEV₁% predicted<50; GOLD4, FEV₁% predicted<30; PaCO₂, arterial partial pressure of carbon dioxide; PaO₂, arterial partial pressure of oxygen.

Table 3 The Clinical Outcomes of Study Population

Variables	Non-PHD Group (n=3277)	PHD Group (n=1109)	P value
Total cost ($)	1407.49 [1019.07, 1984.91]	1463.44 [1092.17, 2046.27]	<0.01
Drug cost ($)	542.35 [356.96, 804.73]	558.55 [386.06,868.34]	0.010
Exam cost ($)	592.13 [409.71,876.81]	602.46 [428.26,869.71]	0.320
Length of stay (day)	9 [7,12]	10 [7,13]	<0.01
30 ±2 days-readmission	90 (2.75%)	30 (2.71%)	0.942
30 ± 2 days-COPD related readmission	67 (2.04%)	23 (2.07%)	0.952
Death from admission to 30 ± 2 days after discharge	8 (0.24%)	7 (0.63%)	0.072

Notes: For continuous variables, median and interquartile range were described to non-normal data. For categorical variables, frequencies and percentages were demonstrated. The costs were transformed to US dollars using the average exchange rate in 2019 (one US dollar was equivalent to 6.90 yuan) because most subjects were enrolled in 2019.

Abbreviations: Non-PHD, without pulmonary heart disease; COPD, chronic obstructive pulmonary disease; 30 ± 2 days-readmission, patients readmitted for all cause within 30 ± 2 days after discharge; 30 ± 2 days COPD-related readmission, patients readmitted for COPD within 30 ± 2 days after discharge.

Table 4 Multivariate Adjusted Relative Risk for Total Cost and Drug Cost in Study Population

	Total Cost	P value	Drug Cost	P value
	RR (95% CI)		RR (95% CI)
Age	1.005 (1.001–1.008)	0.011	1.004 (1.002–1.007)	<0.01
Sex	1.089 (0.991–1.198)	0.076	1.028 (0.963–1.098)	0.404
Smoker	1.003 (0.922–1.091)	0.944	1.001 (0.944–1.061)	0.976
FEV1%predicted	0.890 (0.769–1.030)	0.117	0.932 (0.844–1.030)	0.170
Pulse	1.003 (1.001–1.005)	0.011	1.005 (1.004–1.007)	<0.01
CAT	1.012 (1.007–1.017)	<0.01	1.016 (1.012–1.019)	<0.01
Frequency of hospitalization due to AECOPD in past year	1.056 (0.987–1.129)	0.114	1.036 (0.989–1.085)	0.138
Bronchiectasis	1.052 (0.962–1.151)	0.268	1.038 (0.976–1.104)	0.230
Thromboembolism	1.267 (1.139–1.410)	<0.01	1.343 (1.246–1.449)	<0.01
Cancer	1.332 (1.076–1.650)	<0.01	3.067 (2.629–3.579)	<0.01
Coronary heart disease	1.065 (0.976–1.162)	0.158	1.142 (1.075–1.213)	<0.01
Diabetes mellitus	1.090 (0.977–1.216)	0.125	1.061 (0.984–1.145)	0.121
PHD	1.002 (0.930–1.080)	0.949	1.057 (1.003–1.113)	0.037

Notes: Smoker included former smoker and current smoker; thromboembolism included pulmonary thromboembolism and venous thromboembolism.

Abbreviations: RR, relative risk; FEV₁, forced expiratory volume in one second; CAT, COPD assessment test; AECOPD, acute exacerbation of chronic obstructive pulmonary disease; PHD, pulmonary heart disease.

Table 5 Multivariate Adjusted Relative Risk for Length of Stay in Study Population

	RR (95% CI)	P value
Age	1.019 (1.004–1.033)	0.011
Sex	1.315 (0.915–1.890)	0.138
Smoker	1.022 (0.740–1.411)	0.897
FEV1%predicted	0.744 (0.421–1.313)	0.307
Pulse	1.015 (1.007–1.024)	<0.01
CAT	1.071 (1.052–1.092)	<0.01
Frequency of hospitalization due to AECOPD in past year	1.769 (1.365–2.292)	<0.01
Bronchiectasis	1.022 (0.724–1.444)	0.900
Thromboembolism	4.397 (2.926–6.610)	<0.01
Cancer	5.270 (2.290–12.130)	<0.01
Coronary heart disease	2.407 (1.723–3.362)	<0.01
Diabetes mellitus	1.251 (0.822–1.904)	0.296
PHD	2.028 (1.524–2.699)	<0.01

Notes: Smoker included former smoker and current smoker; Thromboembolism included pulmonary thromboembolism and venous thromboembolism.

Abbreviations: RR, relative risk; FEV₁, forced expiratory volume in one second; CAT, COPD assessment test; AECOPD, acute exacerbation of chronic obstructive pulmonary disease; PHD, pulmonary heart disease.